A US air assault that mistakenly killed at least 30 guests at an Afghan wedding was part of a larger operation targeting Taliban fighters in the area, the Pentagon said today.

The US has not apologised for Monday's raid on the village in the southern Oruzgan province, but attempted several damage limitation exercises as anger grows in Afghanistan over its military presence.

In the first anti-American protests since the fall of the Taliban, about 200 Afghans today marched through the streets of Kabul to express outrage over the attacks.

The demonstrators, about half of them women dressed in burqas, blocked traffic in the dusty capital.

"We support coalition measures against the Taliban regime and al-Qaida, but we cannot tolerate more innocent victims in our country and American bombardment of civilian targets," said Theyba, one of the protest organisers, reading to the crowd from a petition outside the UN headquarters in the city.

The US military has said an AC-130 gunship that retaliated after US aircraft came under ground fire may have been responsible for the deaths in Kakarak.

But the government in Kabul and survivors of the raid say that the shooting from the wedding was from small arms fired in celebration.

Lieutenant General Gregory Newbold of the US Marines yesterday told reporters at the Pentagon that US and coalition troops had fought gunbattles in Oruzgan province with enemy forces in the days before the raid.

All six sites attacked by the gunship had been observed and pinpointed by US soldiers before the AC-130 flew into the area, he said.

But such explanations are unlikely to satisfy those in the country who see a series of mistaken airstrikes as evidence that the US is not concerned about Afghan lives.

"In case of further such incidents, Afghans may start becoming really hostile towards Americans. And that does not bode well for peace in this country," said Hakim, a law student in Kabul.

The Afghan president, Hamid Karzai, demanded earlier this week that the US take "all necessary measures" to avoid further civilian casualties.

Some Afghans believe Mr Karzai owes so much of his power to the US that he is afraid of angering Washington.

"What is this 'all necessary measures'?" asked Safiqulluh, a jewellery merchant. "He should have told the Americans: if this happens again; out of our country.

"The Americans didn't even say 'we are sorry' for what happened. Probably they'll soon say it was Afghans who killed women and children at that wedding party."

Since the Taliban fled Kabul in November 2001, anti-US sentiment has been rare. Many Afghans wanted a larger US presence in their homeland, fearing that without foreign troops, their own leaders would resort to widespread killing.

A Pentagon spokeswoman, Victoria Clarke, yesterday told reporters it was too early to tell whether the US attacks had killed and injured civilians.

She said that an US-Afghan investigation team has reported seeing evidence of damage and some blood but no bodies or graves.

"We just don't have enough information to believe or disbelieve anything at this point," she said.